Yangtze River Pollution: A Troubling History

The Yangtze River in China is the third-longest river in the world and is the largest source of fresh water in the country, supporting over 400 million people. However, the river has become severely polluted over the years, with nearly half of the people depending on it lacking safe drinking water. The pollution is caused by a variety of factors, including industrial wastewater discharge, agricultural chemical fertilizer, ship garbage, and acid rain. The Chinese government has taken measures to control and improve the situation, but the fight against pollution remains challenging, and the river continues to be a source of environmental and health threats.

Industrial wastewater discharge

The Yangtze River basin covers 19 provinces in China and is the main source of water for almost 600 million people. The area along the banks of the river is one of the most prosperous regions in China, with a rapidly increasing population. This has led to an increase in living waste and pollution, as well as industrial activity that contributes to the discharge of wastewater into the river.

Many factories along the Yangtze River have been responsible for discharging sewage directly into the river, which has been a leading cause of pollution. While the amount of wastewater has been substantially reduced due to increased control measures, the water quality of the Yangtze River will take a long time to recover. Some factories still continue to discharge wastewater into the river secretly, further contributing to the problem.

The Chinese government has implemented various measures and regulations to control and improve the situation. For example, in 2021, the Ministry of Ecology and Environment launched a dedicated campaign to reduce water pollution from industrial parks in the Yangtze belt, resulting in the construction of new centralized wastewater treatment facilities and pipelines for sewage collection. Additionally, the government has set targets to reduce the number of tailings dams, which pose a significant threat to the environment, and to improve the recycling of animal waste from livestock and poultry farms.

The pollution of the Yangtze River has also drawn international attention, with the World Bank approving loans to enhance ecological protection and reduce water pollution in the basin. These efforts aim to strengthen ecosystem management, improve wastewater treatment, and address issues such as plastic waste and climate change.

Agricultural chemical fertiliser

Since the reform and opening up of China in 1978, agricultural environmental pollution in the Yangtze River Economic Belt has worsened due to the rapid growth of chemical fertiliser consumption. The increase in chemical fertiliser use has resulted in excess nitrogen discharge into the groundwater and surface water of the river system. This has led to eutrophication, particularly in the river's estuary and lakes, causing excessive nitrogen and phosphorus levels. Eutrophication has had severe ecological consequences, such as the annual blue-green algae bloom in Taihu Lake, which required the salvage of 26,000 tons of algae in 2007.

The agricultural pollution has also contributed to the high levels of heavy metals found in the river's mainstream water. Elements such as zinc (Zn), cadmium (Cd), lead (Pb), arsenic (As), copper (Cu), nickel (Ni), and chromium (Cr) have been detected, with higher concentrations on the left bank of the river. These heavy metals are associated with agricultural activities, as they are present in pesticides and fertilisers, and enter the river through soil runoff and atmospheric precipitation.

To address the issue of agricultural pollution, the Chinese government has implemented measures to reduce chemical fertiliser application. For example, in 2006, the control of agricultural source pollution and the reduction of chemical fertiliser use were included in the 11th Five-Year Plan for National Economic and Social Development. Additionally, the World Bank has approved loans to enhance ecological protection and reduce water pollution in the Yangtze River basin, which includes improving wastewater treatment and reducing pollution from plastics and animal manure. These efforts are crucial to protecting the Yangtze River, which is a vital source of water for millions of people and supports a significant portion of China's GDP.

Ship garbage

The Yangtze River, the third-longest river in the world, has been facing a major pollution problem. One of the key contributors to this issue is ship garbage. The river, which serves as a major economic hub for the region, has a well-developed shipping industry, with numerous ships sailing up and down its waters every day. Unfortunately, this high volume of shipping activity has led to significant pollution.

Ships travelling along the Yangtze River have been known to discharge untreated living waste and sewage directly into the river. In 2015, the amount of rubbish from ships on the Yangtze River reached a staggering 75,000 tons, while the volume of living sewage discharged was 360 million tons. This has resulted in the river becoming heavily polluted with solid trash, including ubiquitous plastic. The high levels of plastic pollution in the Yangtze River are not only detrimental to the river itself but also contribute to the broader issue of plastic waste in the world's oceans. It is estimated that the Yangtze River carries 333,000 metric tons of plastic into the oceans each year, making it the worst culprit among the Asian rivers that contribute to the Great Pacific Garbage Patch.

The Chinese government has recognised the severity of ship pollution in the Yangtze River and has taken steps to address this issue. In May 2022, the Supreme People's Procuratorate (SPP) launched a campaign to tackle ship pollution along the river, filing 602 cases related to administrative public interest litigation. Additionally, local governments have implemented strategies to control Yangtze River pollution, and new regulations to prevent and control ship pollution have been enforced by the Shanghai Municipality and Jiangsu Province, which came into effect in March 2023.

The pollution from ships has had a detrimental impact on the river's ecosystem and the species that depend on it. The Yangtze River was once home to Chinese river dolphins, but due to the degradation of the river's water quality, these dolphins are no more. Other species, such as the Chinese alligator, Chinese paddlefish, and Korean sturgeon, are also facing similar threats. The river's pollution has also affected bird populations, with migratory birds avoiding the polluted areas. However, recent efforts to regulate industry and clean up the water have shown promising results, with an increase in the number of migratory birds observed in 2023.

While progress is being made, the fight against ship pollution in the Yangtze River remains an ongoing challenge. The high volume of shipping activity, coupled with inadequate waste management systems, continues to contribute to the degradation of the river's water quality. It is crucial for authorities to continue enforcing regulations, improving waste treatment processes, and promoting sustainable practices among the shipping industry to mitigate the environmental impact of ship garbage in the Yangtze River.

Acid rain

Agricultural chemical fertilisers and pesticides used in the surrounding fields have been washed into the river during rainfall, causing eutrophication. This process has led to excessive nitrogen and phosphorus in the water, resulting in the growth of blue-green algae. In 2007, an annual algae bloom salvage in Taihu Lake removed 26,000 tons of blue-green algae over a period of six months.

In addition to agricultural runoff, the Yangtze River has also been impacted by industrial wastewater discharge. There are numerous chemical plants, oil refineries, steel mills, and other industrial facilities located along its banks. These industries have been discharging untreated sewage and waste directly into the river, contributing to the high levels of pollution. The river has been found to contain high concentrations of trace elements, including arsenic, lead, cadmium, chromium, copper, and zinc, which pose a significant risk to human health and the environment.

To address the pollution crisis, the Chinese government and local authorities have implemented various measures. The central government has ordered chemical companies to rectify their operations or face closure, and all factories have been instructed to relocate at least one kilometre away from the waterfront. Efforts have also been made to optimise the layout of sewage outfall into the river. Additionally, the World Bank has approved a US$200 million loan to enhance ecological protection and reduce water pollution in the Yangtze River basin. This financing aims to improve wastewater treatment, reduce plastic pollution, and protect land-based ecosystems.

Microplastics

The Yangtze River, the longest river in Asia and the third-longest in the world, is recognised as one of the most microplastic-polluted rivers. Microplastics are widespread in the freshwater environment of China, and the abundance of microplastics is positively correlated with both intensive human activities and urbanisation. The risk index of microplastics in the Yangtze River is 9.20 × 10^5 items/km^2.

Domestic wastewater is the primary source of microplastics in the Yangtze River near urban areas. Other sources include surface runoff, atmospheric transportation, and aquaculture. The distribution of microplastics is influenced by both natural conditions and anthropogenic activities, with the latter playing a more significant role in upstream areas.

The abundance of microplastics in the surface water at the mouth of the Yangtze River was found to be higher on the east and west corners of Chongming Island. The highest abundance of all surface water samples was at site Y5, next to the East China Sea. Microplastic pollution in the upper reaches of the Three Gorges Reservoir has also been identified as a cause for concern.

While there have been studies on microplastics in the Yangtze River, the research has been fragmented, and a systematic understanding of microplastics in the entire river basin is lacking. The complex distribution of microplastics and the limitations of sampling methods present challenges in fully comprehending the extent of microplastic pollution in the Yangtze River.

Frequently asked questions